BALTIMORE—A panel of Medicare advisers has refused to endorse a brain scan that detects beta-amyloid plaques. Experts say that the procedure could play a key role in clinical management and drug research for Alzheimer’s disease.
Members of the Medicare Evidence Development and Coverage Advisory Committee said that they need considerably more data before they can recommend that the Centers for Medicare and Medicaid Services reimburse doctors for the procedure.
“We are all eager to decrease the burden of Alzheimer’s, but the real question, which the committee worked hard to answer today, is, ‘How will this test help us to do that?’” said Rita Redberg, MD, committee chair and Professor of Medicine at the University of California, San Francisco, School of Medicine. “The question we have to keep in mind is whether this test leads to better patient outcomes, or even to better diagnoses. It’s promising, but at this time, we don’t have short- or long-term outcomes for the role amyloid scans can play in the diagnosis or management of people with Alzheimer’s.”
The refusal was a “big disappointment” to neurologists who specialize in Alzheimer’s disease, Maria Carrillo, PhD, Senior Director of Medical and Scientific Relations for the Alzheimer’s Association, said in an interview. But the association has not abandoned its efforts to ensure that the procedure is reimbursed. “We will be recommending to the Centers for Medicare and Medicaid Services that they do consider coverage of beta-amyloid imaging, according to the recommendations we made in the appropriate use criteria” on January 28, she added.
Identifying Appropriate Patient Groups
The criteria identified three patient groups for whom the procedure would be appropriate: patients with persistent or progressive, unexplained mild cognitive impairment; patients with an established dementia syndrome but an atypical presentation or clinical course; and patients whose dementia began at an unusually young age.
“We certainly understand that this [action] requires development of an evidence base, and we do recommend that as well,” said Dr. Carrillo. “But we think there is adequate evidence for the limited use we presented. We will be continuing the studies, but it will take a significant amount of time” to gather the follow-up data the panel requested.
The panel made its decision after hearing several hours of public comment, including physicians’ descriptions of patients’ experiences with the procedure. Howard M. Fillit, MD, Clinical Professor of Geriatrics and Palliative Medicine at Mount Sinai Hospital in New York, used case reports to describe the consequences of negative and positive scans. He described an executive, age 80, who consumed alcohol, took sleeping pills, traveled and had jet lag frequently, and did not exercise. When the patient complained of memory problems, “I diagnosed amnestic [mild cognitive impairment] and started him on acetylcholinesterase inhibitors,” said Dr. Fillit.
The patient’s amyloid PET scan was negative, “much to my surprise,” Dr. Fillit said. Three months after reducing his use of alcohol and sleep medication, modifying his travel habits, and increasing his amount of exercise, the patient was cognitively normal. Dr. Fillit discontinued the acetylcholinesterase inhibitors. The patient “remained in the business he loved and didn’t have to resign from life,” he said.
A symptomatic female patient who could not afford the scan had to leave her job without receiving disability benefits. “She is now being forced to wait in limbo for the test of time,” said Dr. Fillit.
Most committee members noted that beta-amyloid imaging has had anecdotal benefits. But for reimbursement approval, the committee requires data that directly link the test to patient outcomes, including improvements in disease management and quality of life.
Those data are scarce, said Steven Pearson, MD, President of the Institute for Clinical and Economic Review. The institute recently published a white paper that aimed to define the standards by which evidence will be evaluated for determining insurance coverage of diagnostic tests for Alzheimer’s disease.
Only one of 15 amyloid PET studies directly examined how the scan might affect patient outcomes. That industry-sponsored study examined how the scan would have affected clinical decision making for 229 patients evaluated for cognitive complaints, said Dr. Pearson. The patients were selected by memory disorder specialists. Clinicians reviewed patients’ initial symptoms and clinical findings and gave working diagnoses and management plans before and after a scan.
The scan resulted in a change of diagnosis for 55% of the cases, and clinicians reported an average increase of 22% in their diagnostic confidence. After seeing the results, 87% of physicians said that they would change at least one thing in their clinical management plan.
Of the 86 patients initially diagnosed with probable Alzheimer’s disease, 12% had a negative scan, which effectively ruled out the disorder. Half of these patients discontinued the Alzheimer’s medications that they had been taking.